Continuous metallurgical treatment of raw materials



J. LOH'SE May 15, 1945.

CONTINUOUS METALLURGICAL TREATMENT OF RAW MATERIALS Original Filed Marchso. 1943 mmlum n An additional advantage can be obtained according to myinvention by providing the furnace with a regulable burner, which can beadjusted completely automatically by the use of known regulating means.By the use of a completely automatic device of this nature the roastingoperation can be carried out independently to the skill of the man incharge, so that a certain roasting process having a certain roastingaction can be adjusted once and for all solely on the basis of testscarried out in the laboratory.

My invention is illustrated by way of example in the accompanyingdrawing, in which Fig. 1 shows diagrammatically in elevation and inpartial section a plant in which roasting is performed in an open flamecurrent.

Fig. 2 is a sectional view on the line II-II in Fig. 1.

Fig. 3 is a partly sectional view on a larger scale of the burner shownin Fig. 1 diagrammatically.

Fig. 4 is a section on the line IV--IV in Fig. 3 showing more clearlythe distribution of the intake pipes of the burner.

Fig. 5 is a sectional view along the line V-V in Fig. 1.

Fig. 6 is an enlarged detail showing the feeding mechanism.

In Fig. 1 the material is introduced together with the requisite coalinto the hopper l in a disintegrated condition approximately equivalentto a screen mesh of -40. The ground material is discharged through thepipe 2 to a screw conveyor 26 in the burner 3. In the burner nozzle 4there is an intimate mixing of the materials employed, for example oil,gas, coal and sulphide ores with secondary and primary air, withsimultaneous agitation, so that after ignition of the flame the latterwhirls in the form of a long conical flame 8a in the bricked conicaljacket 8 of the furnace.

The burner structure comprises an air chamber 23 which encloses thenozzle structure 4 and opens at its forward end into the furnace 8,around the nozzle 4 at 24. Extending through the rear end of the airchamber and into the rear of the nozzle 4 is a screw conveyor tube 25 inwhich is a screw conveyor 26 supported upon a tubular shaft 27. Into thescrew conveyor there opens the three inlets 3b, 3a and .30, the inlet 3breceiving the pulverized ores, while roasting gas and coal dust are fedinto the conveyor tube 25 by way of the inlets 3a and 3c respectively.

Fuel oil under pressure is fed through the pipe 28 to a suitable feedring 29 surrounding the rear end of the tubular screw conveyor shaft 21from which ring the fuel passes into the tubular shaft by way ofapertures 29. This fuel is discharged at the forward end of the shaft intheburner nozzle 4 where it mixes with the gas, powdered coal andminerals to be blown into the furnace.

The rear end of the screw shaft is connected with a rotor 2| which isdriven by compressed air supplied through the pipeline 22 through asuitable nozzle against blades forming a part of the rotor 2i, and bythis means the screw is turned to feed the several materials to theburner.

" The air employed for driving the rotor 2| passes out of the rotorcasing into the pipe line 33 and is discharged in the air chamber 23, asshown.

In the forward end of the burner nozzle I there is disposed the needle34 which is axially adjustable' within the nozzle to regulate or varythe size of the same. This needle 34 is carried upon the ill forward endof a tubular stem 35 which extends through the tubular shaft 21 andthrough the rotor 2i and is freely rotatable in the shaft and rotor aswell as being axially movable therein. The tubular stem 35 passesthrough and is threadably coupled with a fixed supporting nut 35 whichis located upon the side of the rotor 2i remote from the nozzle and thestem carries a pulley 3? about which is engaged a driving belt 3'!which, in the manner hereinafter described transmits rotary motion tothe stern and also moves axially of and with the stem when the latter isadvanced or retracted for changing the position of the needle in thenozzle 4.

The numerals 38 and 39 designate air feed channels which lead from acompressed air chest an respectively, to the rear end of the burnernozzle 4 and the air chamber 23. The numeral ill designates the airinlet for the air chest. The aforementioned air pipe 22 is branched offthe channel 38. Within the air chest 40 are valves 42 and 33, which areunder the control of suitable automatic regulating mechanism forgoverning the flow of air through the feed channels 38 and 39.

The valves. and 43 are secured to a shaft 40f which is in screw threadedconnection with a wall of the air chest 40 through which it passes.

The regulating mechanism for the valves comprises a pair of gear wheels406 one of which is mounted upon the shaft AM to impart rotary motionthereto and also to have the shaft move axially therethrough wherebyupon the turning of the gears the shaft 40) will be rotated and willalso be axially shifted to move the valves 42 and 43 relative to thefeed channels 38 and 39. The other one of the gear: is operativelycoupled with a motor 40a and this is under direct control of an electricpyrometer 40b. This pyrorneter is electrically coupled with an indicatorsuch as a galvanometer 40c and this in turn is coupled with an energyamplifying means 40d which is actuated by energy from the thermocoupleor pyrometer 40b and actuates suitable electrical control apparatuswhich regulates the supplying of electric current from a source ofsupply to the motor 4011. No detailed illustration of the electricpyrometer, the galvanometer or the energy amplifying means and electriccurrent controlling ap. paratus is believed to be necessary since theconstruction of such devices is well known to tltose versed in theelectrical art as such devices are in daily use. With this controlapparatus, as the electric current induced by the electric pyrometervaries, the variation will be indicated as degrees of heat upon thegalvanometer 43 and these currents will effect the amplifying means ofthe mechanism in unit 40d to increase or decrease the current suppliedto the motor 40a. As the motor 40a is actuated the gear of the pair ofgears Me, which is mounted upon the shaft 40/, will rotate the shaft anddue to the screw connection between this shaft and the wall of the chestthrough which it passes the shaft will be caused to move axially at thesame time that it is rotated.

This regulating mechanism may also be employed for regulating theadmission of air to the rotor 2! in accordance with the air admitted tothe nozzle 4 and also regulate the axial movement of the stem 35 and theposition of the needle in the nozzle 4.

As shown the shaft 40f carries a gear 40h which is moved by the shaft ina direction axially thereof as well as being rotated thereby. Thisaavaeea ear has toothed connection with a relatively wide gear 302'which is coupled with a suitable rotary type valve ldlc which regulatesthe admission of air to the rotor i.

There is also connected with the shaft til the previously referred tobelt 3i which is connected with the pulley 3? carried upon the tubularstem 35. The rear end of this tubular stem 35 is supported in a bearingunit M with which is con nected the pipe line as which may be connectedwith a suitable source of supply of any gases which it may be founddesirable to introduce with. the ore, such as oxidizing or chlorinatingases.

The bearing 3 is in a form to transmit the gases from the pipe to theinterior of the tubular stem 35 through suitable inlets 35 which areformed in the portion of the stem lying within the body of the hearingas is clearly illustrated in Figure 6.

It will be readily obvious from the foregoing that since the tubularstem 35 may readily move axially through the tubular shaft 2?, the rotorand the bearing and since it is in threaded connection with a fixed nut3&3, rotary movement imparted through the medium of the belt 3? from theshaft it will effect the desired axial movement of the stem to move theneedle 36 inwardly or outwardly with respect to the nozzle t. Also sincethe shaft ill moves axially simultaneously with the axial movement ofthe stem 35 the driving belt connecting the shaft MN and stem 35 willmaintain the, proper connection between these elements. The desiredrotation of the air controlled valve ick through the medium of thecoupled gears lilh and 332' is readily eilected even though the gear 6thmoves axially, due to the extreme Width of the gear iiii.

At the opposite end of the furnace there is a discharge section 8?),into which projects a reiractory blast pipe 9 extending approximately tothe base of the two cones of the. double-conical revolving furnace Thisblast pipe has compressed fresh air supplied to the same by the fan orblower unit it through pipe Ma. Another fan it is connected, by means ofp pe 6, centrally to a chamber '5, into which the discharge section 817of the rotating furnace ll projects and out of which the fan it sucksthe sulphurous acid-gas formed during the roasting action, and a part ofthe furnace gas laden with particles of ore which are returned andinjected. through the pipe into the flame corona (funnel) to be againsubjected to the hottest region of the spontaneous preliminar treatmentin the long whirling flame. At la lumps, cakes and coarser particles canbe discharged into trucks, the material in the discharge funnel ofchamber l always forming an airtigt and gastight seal. ore particleswithdrawn by means of fan iii is performed by a special apparatus,comprising a pipe it and an oval shaped chamber l2 (Fig. 5) providedwith filter curtains Md which cause the coarser particles to settleabove the bottom where a conveyor Mb moves them into a series ofdischarge pipes Hie projecting into the above mentioned blast pipe i61a. The air blast therein set up by the blower it! returns thedischarged coarse and line ore particles into pipe 3 as described. Therevolving movement of the conveyor screw Mb is derived from the shaft ofthe fan it over a belting 8h and speed lowering gear 8k. The chamber I 2precedes a filtering tower i6 which may be of any approved constructionand is provided at its lower end. with a centrifugal device Therecycling of the.

or a fine bronze jacket screen it through which the fan it forces thecurrent of sulphurous acidgas and air through bag filters 55. The bronzescreen retains the coarser material and accumulates it in the lowerfunnel portion of the tower it along with the dust falling from thebags, which bags can be subjected to a mechanical shaking operation toassist the separation of the dust.

The filtered gas can be removed by any suitable means for treatment in asulphuric acid plant not shown. The tower it, in which the filter bagsiii are suspended, possesses above the bags a comparatively large emptyspace which during the operation is filled with the combustion ases,which are lighter than sulphur trioxide, so that nitrogen, carbonmonoxide or carbon dioxide are able to escape into the air through apipe ll. This arrangement within the tower it permits of a preliminaryseparation of the flue gases, as carbon monoxide with a specific weightof 0.967, nitrogen with a specific weight of 0.971 and carbon dioxidewith a specific weight of 1.525 will always be displaced upwards inrelation to sul= phur dioxide and sulphur trioxide having specificweights of 2.214- and 2.765 respectively.

It is shown in Fig. 1 that the chamber 8 rotates upon rollers (Fig. 2).The movement is derived irom a motor but over gearing 86. This motoralso actuates, over a shaft 8,? and a belting to, the fan it.

My invention as employed for carrying out the chemicahthermal treatmentfor desulphurization purposes may also be used for performing otherchemical thermal conversion processes, within the bound of protectionsecured by the following claims.

What I claim as new and desire to secure by Letters Patent:

1. An apparatus for the continual metallurgical treatment of raw orematerials in a flame chamher, a burner having an opening communicatingwith one end of the chamber including a constricted throat, means toregulate said burner including a movable core member extending, throughthe burner opening, a conveyor for fuel and raw material to be treatedopening into the burner throat, means for discharging combustion airinto the burner throat adjacent to the com veyor, means for sucking fromthe chamber the gases and particles of material floating therein at theend thereof opposite from said burner, and a discharging device at thesaid opposite end thereof for separating the coarser pieces of materialfrom the material floating on the gases within the chamber.

2. In an apparatus as claimed in claim 1, a reiractory pipe opening outinto the said opposite end of the chamber toward said burner foriniecting a blaster" fresh air into the chamber in opposition to a flameissuing therefrom, and means for producing said blast.

3. An apparatus for the continual metallurgica treatment of raw orematerials in a flame chamber, comprising, an elongated roasting chamber,a burner structure positioned at one end of the roasting chamber, andhaving an opening communicating with the end of the chamber, said Iburner structure including conveyor means positioned to supply rawmaterial to be treated to said chamber through the burner opening and aplurality of air supply means positioned to discharge combustion airadjacent the burner opening to produce a whirling fiamaand also toassist in projecting the material to be treated upon the flame into thechamber, and means for introducing into the chamber a counterblast ofair from the centre of the opposite end of said chamber.

4. An apparatus for the continual metallurgical treatment of raw orematerials in a flame chamber, comprising, an elongated roasting chamber,a burner structure positioned at one end of the roasting chamber andhaving an opening communicating with the end of the chamber, said burnerstructure including conveyor means positioned to supply raw material tobe treated to said chamber through the burner opening and a plurality ofair supply means positioned to discharge combustion air adjacent theburner opening to produce a whirling flame, and also to assist inprojecting the material to be treated upon the flame into the chamber,means for producing into the chamber a counterblast of air from thecentre of the opposite end of said chamber.

5. An apparatus for the continual metallurgical treatment of raw orematerials in a flame chamber, comprising, an elongated roasting chamber,a burner structure positioned at one end of the roasting chamber andhaving an opening communicating with the end of the chamber, said burnerstructure including conveyor means positioned to supply raw material tobe treated to said chamber through the burner opening'and a plurality ofair supply means positioned to discharge combustion air adjacent theburner opening to produce a whirling flame and also to assist inprojecting the material to be treated upon the flame into the chamber,means for introducing into the chamber a counterblast of air from thecentre of the opposite end of said chamber, means for revolving saidelongated roasting chamber about its longitudinal axis, said roastingchamber being so positioned as to discharge therefrom coarser materialcollecting in the bottom position thereof, said discharge preferablydisposed at the end for the introduction of the counterblast.

6. An apparatus for the continual metallurgical treatment of raw orematerials in a flame chamber, comprising, chamber, a burner structurepositioned at one end of the roasting chamber and having an openingcommunicating with the end of the chamber, said burner structureincluding conveyor means positioned to supply raw material to be treatedto said chamber through the burner opening and a plurality of air supplymeans positioned to discharge combustion air adjacent the burner openingto produce a whirling flame, and also to assist in projecting thematerial to be treated upon the flame into the chamber, and means forintroducing into the chamber a counterblast of air from the centre ofthe opposite end of said chamber and means for revolv'ng said elongatedroastin chamber about its longitudinal axis, said roasting chamber beingso positioned as to discharge therefrom coarser material collecting inthe bottom position thereof, said d scharge preferably disposed at theend for the introduction of the counterblast.

7. An apparatus for the continual metallurgical treatment of rawmaterials in a flame chamber, comprising, an elongated roasting chamber.a burner-structure positioned at one end of the roasting chamber andhavng an opening communicatlng with the end of the chamber; said burnerstructure including conveyor means posit oned to supply raw particles ofore material to be treated to said chamber through the burner openingand a plurality of air supply means positioned an elongated roasting as/mesa to discharge combustion air adjacent the burner opening to producea whirling flame and also to assist in projecting the particles of orematerial to be treated upon the flame into the chamber, means forproducing into the chamber a counterblast of air from the centre of theopposite end of the chamber, means for withdrawing from the roastingchamber a part of the roasting gases and particles of ore floatingtherein, and means for recycling the withdrawn gas and particles intothe chamber in conjunction with the counterblast of air.

8. An apparatus for the continual metallurgical treatment of rawmaterials in a flame chamber, comprising a burner structure positionedat one end of the flame chamber and having an opening communicating withthe end of the chamber, said burner structure including conveyor meanspositioned to supply raw material to be treated to said chamber throughthe burner opening and a plurality of air supply means positioned todischarge combustion air adjacent the burner opening to produce awhirling flame and also to assist in projecting the material to betreated upon the flame into the chamber, means for introducing into thechamber a counterblast of air from the centre of the opposite end of thesaid chamber, means for withdrawing from the roasting chamber a part ofthe roasting gases and particles of ore floating therein, and means forrecycling the withdrawn gas and particles into the flame in conjunctionwith the counterblast of air.

9. An apparatus for the continual metallurgical treatment of raw orematerials in a flame chamber, comprising, an elongated roasting chamber,a burner structure positioned at one end of the roasting chamber andhaving an opening communicating with the end of the chamber. said burnerstructure including conveyor means positioned to supply raw materialtobe treated to said chamber through the burner opening and a pluralityof air supply means positioned to discharge combustion air adjacent theburner open- (ill ing to produce a whirling flame and also to assist inproject'ng the material to be treated upon the flame into the chamber,means for introducing into the chamber a counterblast of air from thecentre of the opposite end of the chamber, means for revolving saidelongated roasting chamber about its longitudinal axis, said roastingchamber being so positioned as to discharge therefrom coarser materialcollecting in the bottom position thereof, said discharge preferablydisposed at the end for the introduction of the counterblast, means forwithdrawing from the roast ng chambera part of the roasting gases andparticles of ore floating therein, and means for recycling the withdrawngas and particles into the flame in conjunction with the counterblast ofair.

10. An apparatus for the continual metallurgical treatment of raw orematerials in a flame chamber, comprising, an elongated roastin chamber,a burner structure positioned at one end of the roasting chamber andhaving an opening communicating with the end of the chamber, said burnerstructure including conveyor means positioned to supply raw material tobe treated to said'chamber through the burner opening and a plurality ofair supply means positioned to discharge combustion air adjacent theburner opening to produce a whirling flame, and also to assist inprojecting the material to be treated upon the flame into the chamber,means for introducing into the chamber a counterblast of air from thecentre of the opposite end of said chamber, said elongated roastingchamber having an extended internal circumference at the region wheretheflame is produced.

11. An apparatus for the continual metallurgical treatment of rawmaterials in a flame cham ber, comprising, an elongated roastingchamber, a burner structure positioned at one end of the roastingchamber and having an opening communicating with the end of the chamber,said burner structure including conveyor means positioned to supply rawparticles of ore material to be treated to said chamber through theburner opening and a plurality of air supply means positioned todischarge combustion air adjacent the burner opening to produce awhirling flame, and also to assist in projecting the particles of ormaterial to be treated upon the flame into the chamber, means forintroducing into the chamber a counterblast of air from the centre ofthe opposite end of the chamber, means for withdrawing from the roastingchamber a part of the roasting gases and particles of ore floatingtherein, and means for recycling the withdrawn gas and particles intothe chamber in conjunction with the counterblast of air, said elongatedflame chamber gradually increasing in diameter up to a region where theflame is distended into a hollow cone by action of the counterblast.

JULIUS LOHSE.

